Go fmt formatter

Purpose & User Intent: The Go fmt formatter analyzes Go source code and rewrites it to match the standard gofmt style. Primary users are Go developers, code maintainers, editors, and CI pipelines that require deterministic formatting before commits or automated reviews. It supports preparing diffs, enforcing a common baseline, and improving readability in large codebases.
Core Logic & Features: Required: parse input Go source and apply formatting with the Go standard library formatter, returning the formatted code and a success indicator. Optional/advanced: in-memory multi-file formatting, newline normalization, and batch processing to handle many files in one run; comments are preserved and indentation is standardized according to tabs.
Inputs & Outputs: Inputs: code (string, UTF-8, sample provided). Outputs: formatted_code (string), status (string), parse_error (string, empty on success). Validation ensures the input is valid Go source before formatting; otherwise an error is returned without altering content.
Algorithms & Calculations: The implementation delegates to the Go standard library go/format to perform canonical formatting; the result is deterministic for a given input. If the input cannot be parsed as Go, the formatter returns a parse_error with details. No semantic analysis or lint rules are applied.
Error & Edge Cases: Empty input yields empty formatted output with a success status. Non-Go content or invalid syntax yields a structured error without modifying code. Very large files are processed in streaming-friendly chunks if supported, otherwise wrapped by the host. Line endings in output are normalized to LF by default.
Industry/Region & Localization: UTF-8 encoding; formatting rules are locale-agnostic and consistent across regions. Standard Go environments are assumed.
Assumptions & Exclusions: Assumes input is Go source code; does not perform linting, semantic fixes, or language translation. Not designed to format non-Go languages or embedded code outside of Go source files.